Fitting the Fan Into a Wrong-Size Hole

When the wall fan in our downstairs bathroom quit, I figured we could easily replace it, so I took measurements and bought one that had the same dimensions as the old fan. It did, however, have a different arrangement for the fan and exhaust port. But I thought it would easily fit the space occupied by the old unit.

It didn't take long to remove the old fan, because the back was easy to access from an unfinished section of the basement. It looked like the job would take only a few minutes. Unfortunately, the fan body would not go through the old cutout from the bathroom side due to the arrangement of the fan chamber and exhaust port. The fan manufacturer got a strongly worded letter afterward about poor engineering of a product billed as a drop-in replacement.

I could get at the hole in the wall from the basement side, but mounting flanges along the front edge of the fan prevented me from pushing the fan through from the basement side. The fan was just too big. I had no room to cut the drywall to make a bigger hole. After a while, it dawned on me if I couldn't make the hole bigger, I could make the fan smaller.

Here's how I did it. I made a cut with a hacksaw at about the middle of each flange, which let me push in, or deform, the fan body so the front looked like a four-pointed star. Thus, the outside dimensions of the flange became smaller, and the front of the fan easily passed through the opening. Then I "expanded" the front of the fan box back into a square and secured it in place with several screws into the wood around the original hole.

This entry was submitted by Jon Titus and edited by Rob Spiegel.

Jon Titus has designed electronic equipment, and is a contributing technical editor for Design News. He worked as chief editor of EDN and Test & Measurement World magazines for many years. He now lives in the Salt Lake Valley in Utah.

After bad experiences with several contractors (and "helpful" friends) in our first house my wife and I decided for most jobs we would learn how to do something, buy the right tools, and do the work ourselves. Getting good information is critical, although we all run into unexpected problems. Having the right tools is critical, too--as is knowing how to use them. Thankfully, companies such as Home Depot and Lowe's have excellent tool-rental sections and employees can demonstrate how to use the tools before we take them home. These stores also have hands-on training sessions as well as a stock of well-illustrated books that explain how to tackle projects.

It's the same issue putting audio speakers in the wall, and even more so in cars. I find that, when you do it yourself (when "self" is either contractor or you), things never quite fit.
I was incredibly impressed when my carpenter brother-in-law built a fancy cabinet for a client on an uneven floor and he made it perfectly plumb and also made it look straight by appropriately angling the wood veneer. There's a guy I want doing my fans and speakers.

I have three places, one is a 110 year old board on board construction (no studs in weight bearing or exterior walls), a 80 year old brick bungalow and a 65 year old cabin in the sticks. All have their challenges, with the 110 year being the most interesting. Try fitting door jambs and windows into a 2 inch thick wall, luckily they're solid straight grain fir, so the items mount solid, just need lots of spacing to look right....

I beleive that is why people like NORM ABRAM & TOM SILVA on THIS OLD HOUSE are invaluable in your neighborhood. As someone who has been raised in a family of trades people, and who has spent many decades working on various home construction projects for family & close friends, I can attest to the incredible lack of CARE, FORESIGHT, CONCERN, & EFFECT of many licensed contractors & repair individuals. What I have seen has made me shudder with disbelief. especially in recent times. I believe that modern conditions have dictated so much overhead on the part of many contracting businesses that they are required to hire less-qualified, but quick workers to do as many jobs in as short a time frame as possible. Why else would obvious shortcuts be implemented?????

As far as seeking advice from either LOWES or HOME DEPOT personnel is concerned, I believe that is a relic of a time long ago also. There was a time when you could go into a HOME DEPOT and ask the person in a particular aisle for advice / guidance, etc. Many of the fellows (and ladies) that were there were professionals in these areas. Not any more. I've asked countless questions in the several HOME DEPOT & LOWES outlets in this area, and they all look at me as if I was speaking a foreign language. Furthermore, competition has reduced the numbers of "experts" in the aisles to a relative few. The concept of a self-service store is being more fulfilled as time progresses.

I have had good experiences renting tools from Home Depot in the US and Canada. The people in the tool-rental section explained how to use the tools, let me know about any consumable items needed--lubricant, sanding disks, nail strips, and so on. The tools were well cared for and much better overall than the quality of tools I've found at "rental centers" that rent everything from party "stuff" to jack hammers. I also find knowledgable people (usually the old timers with a lot of experience) in hardware stores.

I have never rented any tools from HOME DEPOT or LOWES, so I can't judge for myself the merits or demerits of those transactions. I have a garage full of tools ranging from watchmakers' tools thru carpentry, electrical & plumbing contractors' tools. My need for renting has been nil!

What I commented on was regarding the overall sales assistance & knowledge base of the personnel haunting the aisles. In my many decades of shopping @ HOME DEPOT (for example), I've seen a marked decline in technical ability of those personnel. Here in the Tampa Bay, FL area, we experienced our first HOME DEPOT outlet close to 30 years ago (the early 1980s). When I went to the local store years ago, I was mostly greeted w/ very knowledgeable fellows who not only knew the products on the shelf, but were not hesitant to ask if I knew how to work w/ the item(s). LOWES for us is a relative recent addition. The local store was built on the order of 5 years ago. However, going into either store presently, and asking questions, more often than not is greeted w/ a blank stare. The people manning the aisles (IF you can find one) are for the most part NOT very experienced or knowledgeable with the items in their departments.

I can only surmise that employment conditions at these stores has changed drastically from what it was then. Now, instead of hiring experienced trades people, they are hiring anyone regardless of previous work experience.

My brother-in-law was recently in the process of demolishing his old 1980's-ers kitchen to clear the way for a new one. In the early stages of the process, he noticed that both the electric oven and dishwasher were impossible to remove, because they were literally surrounded by the edges of the front panel of the cabinets. There were no trim pieces to remove to gain clearance--the appliances were literally built in by the custom cabinetry.

On further disassembly, he found that it wouldn't have mattered even if he was able to get clearance around the appliances front edges--both were hard-wired with Romex cables that disappeared into the floor with zero slack. Apparently, whoever built the kitchen placed the dishwasher and oven in place first, hard-wired them in, and then built the cabinets around them, evidently never thinking about the need to one day service or replace the units.

I can only draw a parallel with the heater core on my car, which requires the entire dashboard and HVAC module to be removed to replace it, for some $600 worth of labor to replace a $40 part.

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